Turbine and compressor blading in axial flow internal-combustion turbine power plants



Oct. 14, 1952 w. R. HAWTHORNE 2,613,909

I TURBINE AND COMPRESSOR BLADING IN AXIAL FLOW INTERNAL-COMBUSTION TURBINE POWER PLANTS Filed Jan. 31, 1945 3 Sheets-Sheet 1 Attorney Oct. 14, 1952 w. R. HAWTHORNE 2,613,909

TURBINE AND COMPRESSOR BLADING IN AXIAL. 110w INTERNAL-COMBUSTION TURBINE POWER PLANTS Filed Jan. 31, 1945 '3 Sheets-Sheet 2 Attorney Oct. 14, 1952 w. R. HAWTHORNE 2,613,909

TURBINE AND COMPRESSOR BLADING IN AXIAL FLOW INTERNAL-COMBUSTION TURBINE POWER PLANTS Filed Jan. 51, -1945 s Sheets-Sheet 5 [Hit-1hr t orlmy;

Patented Oct. 14, 1952 TURBINE AND COMPRE SOR" BLADING IN AXIAL FLOW INTERNAL-COMBUSTION TURBINE POWER PLANTS William Bede Hawthorne, SilverflSpring, .Md., as

signor. to Power Jets- (Research and Development) Limited, London, England Application January 31, 1945, Serial No. 575,54?

In Great Britain January 31, 1944 .10 Claims, (ox. 253-3915) This invention "relates to rotor blading of gas turbines and similarly bladed fluid flow maechines in which the working temperature of the blades constitutes a limiting factor in the operation of the machine. I

An object of the invention is proved form of blading for machines of the kind referred to, having improved properties as regards cooling, by providing means whereby heat extracted from the blade part proper, subjected to the working temperature is effectively transferred to another part of the structure, which acts as a heat dissipating means. l

According to the present invention there is provided, in or fora-machine of the kind referred to andespecially a' combustion gas turbine, rotor blading of which ablade part proper which lies in the working fluidchannel of the machine is associated with an extension part which extends, or'in effect extends, the blade structure beyond a boundary of said channel into a cooler zone, said blading having co mmon both to its 1 blade part proper and. to its extension part a closed internal cavitycontaining asuitable coolant mediumselected to be convective in the conto provide an imditions of operation and the relative location of said blade and extension parts, having regard to the arrangement of the blade as a whole, being such. as to provide conditions in which a convective circulationof. the coolant will be set.

up..due to the temperature differential. between said parts. In specifying in the foregoing that:

continuous cycle of evaporation in the blade portion and condensation in the extension part.

It is intended that in use centrifugal force will supersede gravity in determining the location of the coolant in its cavity and will in fact be an important factorin producing the convective circulation desired in a particularly .effective manner, as will be more fully explainedg Accordingly, the invention contemplates that the portion of the cavity in the extension part re? ferred .to-will'lie radially inwards of thesportionv in the'blade part proper so that the coolant will. be centrifuged into the blade part proper in use.

- The invention owes its conception. to the requirements 'o'f andhas particular application to.

the cooling. oflthe' rotori blading-in an axial flow.

gas-turbine power plant comprising an axial flow I compressor system, coaxially nested w ithin an axial flow turbine system and employing twotier combined turbine and compressor blading havinga radially inner part of compressor pro- 1 file and a radially outer part of turbine profile;--- The .invention will accordingly be described detail with reference to the accompanying drawings in relation tosucha plant without prejuthe scope of the appended;

dice, however, to claims. In the drawings- Figure 1 .is' a view in: elevationof a two-tier blade for a combined- 'compressor and turbine of the axial flow type.

Figure 2 is an end towardslthe root. I

Figure 3 is a sectional elevation'of thesame.

Figures 4 and 5 are views in section taken-along the lines 4-4 and 5-5 ofFigure-S.

Figure 6 isa diagrammatical view in axial-sec-- tion of a gas turbine power unit-ofthe type employing two-tier blades. The blade shown in Figure 1. comprises a M and a. further blade portion l3, all integrally formed. The root portion, I0 includesan 'extension l I with serrated orridged flanks adapted tobe secured in acorrespondingly formed groove or slot in a rotor drum or wheel.

The blade. portion I2 is formed of appropriate profile and angle to act as part ofa row ofaxialflow: compressor blading. Similarly, the blade portion I3 is appropriately formed to act as part of a row of axial flow turbine blading. :In Figure 1 the composite blade is viewed inthe axial direction of the turbocompressor of which it is to form part, and inFigure 2 thedirection of rotation is indicated by an arrow R." Arrows A and T, respectively, indicate the directions of flowof air and gas through the compres sor and turbine respectively, the compound blade of the example illustrated being intended for a turbo-compressor combination. operatingon the I contrafiow principle. For a turbocompressor combination-in which turbine and. compressor flowlis in'the'same direction, a composite blade,

according to the invention would. be generally similar to that illustrated but with the-blade angles of the two' blade portions l2l3 appro-* priately. altered.

- It will be noticed that the turbine gitar a of. the composite blade is disposed outwardly of the compressor portion l2 (with-respect to the axis of rotation); For reasons to be hereinafter n explained this disposition'is' an important rat-" view of the same lookin r551! portion.1.l l], a blade element I2, a shroud-portion I l during manufacture before insertingandpere. I0;

manently securing the plug I6.

The material used for the. filling. t1; may: be metallic sodium or a suitable-saltofarelatively: high melting point such as is used as an internal 1 coolant for the exhaust valves of poppet valve reciprocating internal combustion engines and the amount of the filling I! should be such that when 7 it is cold, and therefore in the solid state it'- should occupy less than half vof the total volume 321 2 382 in erna space 15 0f; the 0Omp0Sil3E;1b1ad8;,20

-...'lihei.=;-.abovesde cribed two-tier: hollow: blade: when assembled; in; the. complete. machine an. revealed: Fig... Gaby: the cutting: away of the-casing: or; the machine. the. blade .root; l.0- emsrsecuredito the.- rim of: a. conventional form '25 oizlqtorzwheel l8. Theiinnen compressor portion. tofrthe blade. liesdn; the channel for; .air. flowing iasqindicated by; the arrow A; while .therturbine portiom l;3.. of. the; blade; '1ieS';.in the outer. channel. for hot gas flowing in the same direction asithe; air as indicated by the arrow T. 1

i lhaheat. istconducten inwards along .thezblade fsthcsmner. blade-portiom 12;. thetemperature, of which rises sufiiciently to .melt the. sodiumaor. saltgnllingxllu The latter is thereupon fiung'outwards by centrifugal force to the outer endof the. 110119.?!11115 iwherei itiis inheat; conductive contact withrmerwalls; (if; .thei turbine; portion. I13. of. the blade. As the temperature of the; liquid sodium. OlfixSflllZ; riseslby conduction. from: the. hot: walls 40 Dist-haema i e. portioni l 3. the vapour pressure. rises and the concentration of vapour-intheainner; end: ofrthmhollow; 15; in; contact with. the walls .ofthe inner; compressor blade: portion. l:2-;. is. increased; HQQtareOeiYQd; by; the& liquid sodium; or. saltfrom. hecwalls :of; .thejturbine; blade: portion. is .transferrets by f the; vapour: to} the walls; of: the; come-. Dresser: bladeepoiitioni. 1011i account; of; its;.latent; heat vaporisation, the-Cliquid; sodium' or.-..saltls is canahlaof; receiving-and. transferring-ga=v large amountzofrheatwith atcomparatively small rise. titemperature. theiheat transferred: being; pro.-..v mated}. by: GODYQCHQILCUIIBII'DS;in$11181 liquid-and; vapour phases; of..the1.. cooling medium, which. thusi..-co.ols, theihotturbine part: i3 .012 the. blade 5 veryemciently and..by.: transferring the" heat to.-v thejcooler compressor. part; 12 of therblade, helps t r-.,redu.c.e; the temperature gradienixzwithin-.the-. material. of the bladeitselfi and 1 thus. to minimise internalistresses and-liability to: distortion...

The heatdissipatedfrom. thewallsof: the: com A pressqrmartr l2 ofthe; blade by conduction: or radiation; is, takenup; by. the charg ispassing throu hthe. compressor and. is. therefore not enlost-.4. With a..contra. -flow arrangement-.01 turbine and; compressor. the transfer of'iheat is: toll sqrne ententregenerative;.1

.Ingqrderto; obtain .perfect: balancezof the turbo-l compressor roton'incemorating blades according; to this invention, it is necessary not;only that the; la es; shall berm: perfect; balance without. their filling .cool ne medi m but; that -..pre.cisely.=' the;v im Q ht;1..Q ..QOQli g; medium be. introduced; each blade; It; is; alsonimportant that; the: llfld iitl 1 f; theseveral; bladeslbe dimensioned: 7

#613,909 r j I 4 to finelimits in order that the centres of gravity of the fillings I! when liquid and centrifuged to the outer ends of the hollows l5 shall be equidistant, from theaxis of rotation. g

Itfis essential that the pliigsl l5 adequately secured to withstand the centrifugal force of the liquid fillings l1.

It will be recognized that in the construction illustrated in and described with reference to the,. drawings,.the; inner (compressor) portion l2 of the blade constitutes, in principle, merely a radially inward extension of the outer (turbine) portion. l=3-, beyond. the confines of the hot gas duct: which the part 13 will operate in use,

into. a. cooler zone represented by the compres- 'sion fiduot, fitsi compression function being inci- 7 dental to the main purpose of cooling. It will alsobe appreciated, that, although the invention. has been described in its application to bladeg ezttending radially outwardly fronran innor: rotor, the; basic requirement, called fon.,by* the invention. as; r ar s. sn t n; i er ly. that the; coolant chamber shouldafford forthe; circulation of the coolant, a. pathhaving arad e; ally outward componentfrom the cooler extension-part of a, blade. to. the, blade part.prop,er..; What I claim as my inventionand desirecmii secure-by Letters.Patentis; v I I 1:, A, turbine or similar-1y bladed; flui flow machine. required1 to run .at; high temperatures. and: especially a. combustion, gas tur-bine; comprising a rotor bladingeach-blade 0f,- whichainecludes. a. blade; partpronen ,disposedintheworlrin .--.fluid: channel: nd an: e tensicnq a ihev ns. ablade formation; whic. projects;\into;and.1 r;- efiectextends the bladewtruc re bexond boundary. of saidchannel. intcr- ....c0o;1er zone: which includes. a fluid; flow channel; each; saidqs; blade. having.-eommon bothv to; its blade part: proper; and. to. itst extensiorn partaclosed internak, cavity: containing". acoolantrmedium. only:.par.tlyfilling same; andv convective; in thetconditions; of. operation and. said:.cavity: being arranged .sothat; the coolant mediun'nwill :be centrifugedintoztha. bladerpartit-proper in use, the arrangement being. such; that: due; to: the relative: 1OC3JtiOIII..Of5 said; blade. and. extension: parts, their differential tem.-.- perature; and the.=centrifuging;of the ooolantme-c dium conditions. are, provided inv which: a. convective .circulation...of the. coolant; willv he set:.up;-, inause, and. means 'toz maintain-.- alflow of cooling medium through said'sfluid flowichannel;v 2.: Ages turbine embodying: an. axial flow conrpressor. coaxially nestedzwithin' an axialIfiow turbine', having two-tierblading extending out wardly: in: the. radial sense-- from: an inner rotor f each blade of which inclu'desea blade .part proper acting. as turbine blading'. disposed: in. the Worker ing fluids channel" and a radially-inner extension" part acting. as compressor .bladingi-which' projectsr intoandgineffect extends the blade'structu're be yond an. inner boundary. ofxsaidz channel, each said blade having common to both itsablade part. proper. and toits extension partxaclosediiinternal cavity containing a coolant; medium only. partly f fillingjsame and convectivein the conditionsaofr operation, the: arrangementlthus .beingsuch: that due, toithe; relative: location. on said; parts;. their. differential. temperature and;.the centrifuging or; the coolant: medium,. conditions. are-provided'iint. which aI :convective. circulation J of::- the: coolant; willbesetup; in..use :1 1.5.1:, ;:.=5

3.; Airotor' blade designed: and adapted-f 01:; use

1 in: a; turbine tor similarly; bladed: :fluid zfiowaimaa chine .requiredtorunat high-rtemperatureszandi especially a combustion prisingl in addition to a blade part proper-intended in-use to be disposedinthe working v-fiuid channel, an extension part having a blade. formation which-is intended in-use to project into and in effect extend, the blade structure beyond a boundary of saidchannehsaid blade having common both to its blade-'part-proper and to its extension part a closed internal cavity containing a coolant medium only-"partly filling same and convectivein theconditions of operation and said cavity being arranged so that the coolant medium will be centrifuged into the blade part proper in use, the arrangement being such that due to the relative location of said blade and extension parts and the centrifuging of the coolant medium conditions are provided in which a convective circulation of the coolant will be set up in use if said extension part is kept at a lower temperature than said blade part.

4. A two-tier combined turbine-compressor blade designed and adapted for mounting on the inner rotor of a turbine having blading extending outwardly in the radial sense from an inner rotor and comprising in addition to a radially outer blade part proper designed to act as an axial fiow turbine blade intended in use to be disposed in the working fluid channel, an extension part designed to act as an axial flow compressor blade which lies radially inwardly of said blade part proper and is intended to extend beyond an inner boundary of said channel in use, said blade having common both to its blade part proper and to its extension parta closed internal cavity containing a coolant medium only partly filling same and convective in the conditions of operation, the arrangement thus being such that due to the relative location of said blade and extension parts, having regard to the intended arrangement of the blade as a whole in use and the centrifuging of the coolant that will then take place, conditions are provided in which a convective circulation of the coolant will be set up in use if said extension part is kept at a lower temperature than said blade part.

5. A combined turbine-compressor blade as claimed in claim 4 including an integral shroud portion, adapted to form part of a complete shroud ring in the assembled engine andlocated between the turbine and compressor tiers of the blade, the mentioned internal cavity passing through the said shroud portion.

6. A turbine or similarly bladed fluid flow machine required to run at high temperatures and especially a combustion gas turbine, comprising radially extending rotor blades, each said blade including a radially outer blade part proper lying in the working fluid channel of the machine, a radially inner extension part extending beyond said channel into a cooler zone radially within it, said parts of the blade having a common closed internal cavity, and a coolant medium partly filling said cavity, said medium being selected to be liquid at the temperature of the extension part and vapor at the temperature of the blade part proper in operation, whereby a.

convective circulation of the coolant medium is set up'in the cavity due to the combined eifects of centrifuging and the different temperatures of said parts of the blade.

7. A turbine or similarly bladed fluid flow machine requiredv to run at high temperatures and especially a combustion gas turbine,.comprising means defining an annular channel for working gas turbine and com-'.

fluid and a further channel lying radially within said firstementionedchannel, means for maintaining a flow of cooling fluid throughdsaiid fure,

ther channel, radially extending rotor blades, each said blade includinga radially outer blade part proper lying in said working fluid channel," a lradiallyinner extension part. lying. in said further channel, said parts of, the: blade. having a common closed internal cavity,'.and a'coolant medium partly filling said cavity, saidt medium being selected to be. liquid at the temperature of the extension part and vaporat' the temperature of the blade part proper in operation, whereby a convective circulation of the coolant medium is set up in the cavity due to the combined efiects of centrifuging and the different temperatures of said parts of the blade.

8. A gas turbine plant comprising an axial flow turbine, an axial flow compressor having its annular air flow channel nested coaxlally within the annular gas flow channel of the turbine, and radially extending two-tier rotor blades, each said blade including a radially outer part of turbine blade formation lying in the gas flow channel of the turbine, a radially inner part of compressor blade formation lying in the air flow channel of the compressor, said parts having a common closed internal cavity, and a coolant medium partly filling said cavity, said medium being selected to be liquid at the temperature of the compressor part of the blade and vapor at the temperature of the turbine part of the blade in operation, whereby a convective circulation of the coolant medium is set up in the cavity due to the combined effects of centrifuging and the different temperatures of said parts of the blade.

9. A rotor blade for a turbine or similarly bladed fluid flow machine required to run at high temperatures and especially a combustion gas turbine, comprising a blade part .proper intended to lie in the Working fluid channel of the machine and an extension part intended to extend beyond said working fluid channel into a cooler zone radially within it, said part having a common closed internal cavity, and a coolant medium partly filling-said cavity, said medium being selected to be liquid at the temperature of the extension part and vapor at the temperature of the blade part proper in operation, whereby a convective circulation of the coolant medium is set up in the cavity due to the combined effects of centrifuging and the different temperatures of said parts of the blade.

10. A two-tier rotor blade for a gas turbine plant comprising an axial flow turbine and an axial flow compressor having its annular air flow channel nested coaxially within the annular gas flow channel of the turbine, including a part of turbine blade formation intended to lie in the gas flow channel of the turbine, a part of compressor blade formation intended to lie in the air flow channel of the compressor, said parts having a common closed internal cavity, and a coolant medium partly filling said cavity, said medium being selected to be liquid at the temperature of the compressor part of the blade and vapor at the temperature of the turbine part of the blade in operation, whereby a convective circulation of the coolant medium is set up in the cavity due to the combined efiects of centrifuging and the different temperatures of said parts of the blade.

WILLIAM REDE HAWTHORNE.

(References on following page) smegma l 8;

:.,.:.EREEERENGES Number. Name, Bah hE fOHbWing references" are '0': re'c'o'rcf in the file-' 1)!this?tp'affenti:' I

U I E *Q' PATENTS 2,401,164 Kimba-H. Sept. 3,1946 Number Name. .Da-te v Y k T ihili fifi wmmerwmhmu 0ct'., 2), 1 9l4 v G MTENTS v. momma ma knwmnhumum.1919 mm m Date 

